Continuity mistake: When we first see Lancelot in a close-up sitting on his horse next to his tent there are no jousting sticks anywhere to be seen. Later when King Arthur comes across the bridge we see the tent again and there are many jousting sticks around it and near the flag. (00:46:35 - 00:48:00)????
Revealing mistake: In the scene where Sir Percival is attacked by the peasants, the green floodlights that were used by the crew to enhance the colour of the foliage are reflected in the actor's armour and the blonde hair of a peasant girl.